Pinion lubrication structure of planetary gear mechanism

Abstract

A pinion lubrication structure of a planetary gear mechanism includes a hollow portion, an annular oil catcher, an oil gallery, and an aperture. The annular oil catcher is supported by a carrier to collect oil to flow into the hollow portion. The oil is supplied outward in a radial direction from a central portion of the planetary gear mechanism. The oil is supplied to an inner peripheral surface of a pinion through the oil gallery. The oil gallery extends from an inside of the hollow portion through a pinion shaft in the radial direction. The aperture is provided at an axial end of the pinion shaft to be connected to the hollow portion. A distance from an axis to an outer end of the aperture in the radial direction is smaller than a distance from the axis to an outer end of the hollow portion in the radial direction.

What is claimed is: 
     
       1. A pinion lubrication structure of a planetary gear mechanism that includes a pinion, a pinion shaft that rotatably supports the pinion, and a carrier that rotates around an axis, the pinion lubrication structure comprising:
 a hollow portion provided in the pinion shaft; 
 an annular oil catcher supported by the carrier to collect oil so that the oil flows into the hollow portion, the oil being supplied outward in a radial direction from a central portion of the planetary gear mechanism; 
 an oil gallery through which the oil is supplied to an inner peripheral surface of the pinion, the oil gallery extending from an inside of the hollow portion through the pinion shaft in the radial direction; and 
 an aperture provided at an axial end of the pinion shaft to be connected to the hollow portion, a distance from the axis to an outer end of the aperture in the radial direction being smaller than a distance from the axis to an outer end of the hollow portion in the radial direction, 
 wherein the annular oil catcher includes a tubular oil guide portion that is inserted into an opening provided at an axial end of the pinion shaft, and 
 wherein the aperture is provided between an inner periphery of the opening and an outer periphery of the tubular oil guide portion. 
 
     
     
       2. The pinion lubrication structure according to  claim 1 ,
 wherein a protrusion is provided on an outer peripheral portion of the annular oil catcher, the protrusion covering a part of the aperture. 
 
     
     
       3. The pinion lubrication structure according to  claim 2 ,
 wherein the pinion shaft includes an opening at an axial end of the pinion shaft, 
 wherein the hollow portion and the opening each have a circular shape when viewed on a cross-section taken along a plane perpendicular to an axial direction along the axis, 
 wherein a diameter of the hollow portion is larger than a diameter of the opening, 
 wherein a stepped portion is provided between an inner periphery of the hollow portion and an inner periphery of the opening, and 
 wherein an oil reservoir to hold the oil is provided between the inner periphery of the hollow portion and the stepped portion. 
 
     
     
       4. The pinion lubrication structure according to  claim 2 ,
 wherein the tubular oil guide portion extends through the opening and is inserted into the hollow portion, 
 wherein the annular oil catcher includes an oil catching portion outside the hollow portion to collect the oil, and 
 wherein the oil catching portion is open inward in the radial direction. 
 
     
     
       5. The pinion lubrication structure according to  claim 1 , further comprising:
 a plug that is pressed into the hollow portion from an axial end of the pinion shaft, 
 wherein the annular oil catcher includes a tubular oil guide portion that is inserted from an axial end of the pinion shaft into an opening provided at a center of the plug, and 
 wherein the aperture is provided between an inner periphery of the opening and an outer periphery of the tubular oil guide portion. 
 
     
     
       6. The pinion lubrication structure according to  claim 5 ,
 wherein the pinion shaft includes an opening at an axial end of the pinion shaft, 
 wherein the hollow portion and the opening each have a circular shape when viewed on a cross-section taken along a plane perpendicular to an axial direction along the axis, 
 wherein a diameter of the hollow portion is larger than a diameter of the opening, 
 wherein a stepped portion is provided between an inner periphery of the hollow portion and an inner periphery of the opening, and 
 wherein an oil reservoir to hold the oil is provided between the inner periphery of the hollow portion and the stepped portion. 
 
     
     
       7. The pinion lubrication structure according to  claim 5 ,
 wherein the tubular oil guide portion extends through the opening and is inserted into the hollow portion, 
 wherein the annular oil catcher includes an oil catching portion outside the hollow portion to collect the oil, and 
 wherein the oil catching portion is open inward in the radial direction. 
 
     
     
       8. The pinion lubrication structure according to  claim 1 ,
 wherein the pinion shaft includes an opening at an axial end of the pinion shaft, 
 wherein the hollow portion and the opening each have a circular shape when viewed on a cross-section taken along a plane perpendicular to an axial direction along the axis, 
 wherein a diameter of the hollow portion is larger than a diameter of the opening, 
 wherein a stepped portion is provided between an inner periphery of the hollow portion and an inner periphery of the opening, and 
 wherein an oil reservoir to hold the oil is provided between the inner periphery of the hollow portion and the stepped portion. 
 
     
     
       9. The pinion lubrication structure according to  claim 1 ,
 wherein the tubular oil guide portion extends through the opening and is inserted into the hollow portion, 
 wherein the annular oil catcher includes an oil catching portion outside the hollow portion to collect the oil, and 
 wherein the oil catching portion is open inward in the radial direction. 
 
     
     
       10. The pinion lubrication structure according to  claim 1 ,
 wherein the aperture is an open passageway that extends from the hollow portion to an outside of the pinion shaft. 
 
     
     
       11. A pinion lubrication structure of a planetary gear mechanism that includes a pinion, a pinion shaft that rotatably supports the pinion, and a carrier that rotates around an axis, the pinion lubrication structure comprising:
 a hollow portion provided in the pinion shaft; 
 an annular oil catcher supported by the carrier to collect oil so that the oil flows into the hollow portion, the oil being supplied outward in a radial direction from a central portion of the planetary gear mechanism; 
 an oil gallery through which the oil is supplied to an inner peripheral surface of the pinion, the oil gallery extending from an inside of the hollow portion through the pinion shaft in the radial direction; and 
 an aperture provided at an axial end of the pinion shaft to be connected to the hollow portion, a distance from the axis to an outer end of the aperture in the radial direction being smaller than a distance from the axis to an outer end of the hollow portion in the radial direction, 
 wherein the annular oil catcher includes a tubular oil guide portion that is inserted into an opening provided at an axial end of the pinion shaft, and 
 wherein the aperture is provided by a through-hole extending through an end wall of the pinion shaft in which the opening is provided. 
 
     
     
       12. The pinion lubrication structure according to  claim 11 ,
 wherein the pinion shaft includes an opening at an axial end of the pinion shaft, 
 wherein the hollow portion and the opening each have a circular shape when viewed on a cross-section taken along a plane perpendicular to an axial direction along the axis, 
 wherein a diameter of the hollow portion is larger than a diameter of the opening, 
 wherein a stepped portion is provided between an inner periphery of the hollow portion and an inner periphery of the opening, and 
 wherein an oil reservoir to hold the oil is provided between the inner periphery of the hollow portion and the stepped portion. 
 
     
     
       13. The pinion lubrication structure according to  claim 11 ,
 wherein the tubular oil guide portion extends through the opening and is inserted into the hollow portion, 
 wherein the annular oil catcher includes an oil catching portion outside the hollow portion to collect the oil, and 
 wherein the oil catching portion is open inward in the radial direction. 
 
     
     
       14. A pinion lubrication structure of a planetary gear mechanism that includes a pinion, a pinion shaft that rotatably supports the pinion, and a carrier that rotates around an axis, the pinion lubrication structure comprising:
 a hollow portion provided in the pinion shaft; 
 an annular oil catcher supported by the carrier to collect oil so that the oil flows into the hollow portion, the oil being supplied outward in a radial direction from a central portion of the planetary gear mechanism; 
 an oil gallery through which the oil is supplied to an inner peripheral surface of the pinion, the oil gallery extending from an inside of the hollow portion through the pinion shaft in the radial direction; and 
 an aperture provided at an axial end of the pinion shaft to be connected to the hollow portion, a distance from the axis to an outer end of the aperture in the radial direction being smaller than a distance from the axis to an outer end of the hollow portion in the radial direction, 
 wherein the annular oil catcher includes a tubular oil guide portion that is inserted into an opening provided at an axial end of the pinion shaft, and 
 wherein the aperture which connects the hollow portion in the pinion shaft and an outside of the pinion shaft is located more outward than the tubular oil guide portion in the radial direction. 
 
     
     
       15. The pinion lubrication structure according to  claim 14 ,
 wherein the aperture is provided between an inner periphery of the opening and an outer periphery of the tubular oil guide portion. 
 
     
     
       16. The pinion lubrication structure according to  claim 14 ,
 wherein a protrusion is provided on an outer peripheral portion of the annular oil catcher, the protrusion covering a part of the aperture. 
 
     
     
       17. The pinion lubrication structure according to  claim 14 , further comprising:
 a plug that is pressed into the hollow portion from an axial end of the pinion shaft, 
 wherein the aperture is provided between an inner periphery of the opening and an outer periphery of the tubular oil guide portion. 
 
     
     
       18. The pinion lubrication structure according to  claim 14 ,
 wherein the aperture is provided by a through-hole extending through an end wall of the pinion shaft in which the opening is provided. 
 
     
     
       19. The pinion lubrication structure according to  claim 14 ,
 wherein the pinion shaft includes an opening at an axial end of the pinion shaft, 
 wherein the hollow portion and the opening each have a circular shape when viewed on a cross-section taken along a plane perpendicular to an axial direction along the axis, 
 wherein a diameter of the hollow portion is larger than a diameter of the opening, 
 wherein a stepped portion is provided between an inner periphery of the hollow portion and an inner periphery of the opening, and 
 wherein an oil reservoir to hold the oil is provided between the inner periphery of the hollow portion and the stepped portion. 
 
     
     
       20. The pinion lubrication structure according to  claim 14 ,
 wherein the tubular oil guide portion extends through the opening and is inserted into the hollow portion, 
 wherein the annular oil catcher includes an oil catching portion outside the hollow portion to collect the oil, and 
 wherein the oil catching portion is open inward in the radial direction.